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Publication numberUS4710372 A
Publication typeGrant
Application numberUS 06/911,426
Publication dateDec 1, 1987
Filing dateSep 25, 1986
Priority dateMay 18, 1984
Fee statusLapsed
Also published asCA1254150A1, EP0165454A2, EP0165454A3, EP0165454B1, US4634589
Publication number06911426, 911426, US 4710372 A, US 4710372A, US-A-4710372, US4710372 A, US4710372A
InventorsHans-Ulrich Scheller
Original AssigneeWurttembergische Parfumerie-Fabrik Gmbh
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Containing finely divided apatite
US 4710372 A
A dentifrice for hypersensitive teeth containing at least 15% by weight of an apatite having an average particle size of less than 8 μm and an abrasion value (RDA) of less than 30 as the sole crystalline and polishing substance. No further soluble mineral salts are present in the dentifrice. The dentifrice may also contain a local anesthetic.
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What is claimed is:
1. A dentifrice for hypersensitive teeth containing essentially at least 15% by weight of hydroxylapatite or fluoroapatite of an average of particle size of less than 8 microns and an abrasion value (RDA) of less than 30 as the sole crystalline and polishing substance, the dentifrice containing no further soluble mineral salts.
2. The dentifrice of claim 1 further comprising a local anesthetic.
3. The dentifrice of claim 1, wherein said average particle size is less than 4 μm.
4. The dentifrice of claim 3, further comprising a local anesthetic.

This application is a continuation of Ser. No. 731,286, filed May 7, 1985, now U.S. Pat. No. 4,634,509.


The present invention relates to a dentifrice for hypersensitive teeth containing an apatite having an average particle size of less than 10 μm and, optionally, a local anesthetic.


German Patent Specification No. 21 34 862 describes dentrifrices for hypersensitive teeth. However, the dentifrice recipes additionally contained an osmotically effective salt combination comprising sodium hydrogencarbonate, sodium chloride, magnesium carbonate, magnesium chloride, potassium sulfate, etc.

U.S. Pat. No. 3,122,483 discloses adding strontium chloride to dentifrices, since this substance is believed to influence the stimulus conduction in the pulp. From the view of dental medicine influencing the pulp is hardly desired and may invlove other negative consequences.

A further means for treating hypersensitivities is by local application of amine fluoride solutions. However, this treatment has the drawback of that it can only be carried out in the dentist's office, and, with conventional dental care, will only last for a short time.


Extensive experimental work directed to improving the commercial product described in the German Patent Specification No. 21 34 862 has led to the surprising result that the addition of strontium chloride did not improve the effect. Rather, it was found that the efficacy could be improved to a significant extent by omitting all soluble mineral salts and employing an apatite having an average particle size of less than 8 μm as the sole crystalline and polishing substance. Moreover, such an apatite has an substantially lower abrasion value (measured as RDA; cf. Radioactive Dentine Abrasion, J. J. Hefferren, J. Dental Research 55, No. 4, 563-573 (1976)) of less than 30. The amount of the apatite used must be higher than that of the commercial product, namely at least 15% by weight instead of 9% as used in commercial products to date.

These results were not foreseeable and also cannot be readily interpreted afterwards. However, the findings suggest that there is some polishing effect. Namely, in the course of polishing there is always formed a continuous vitreous glossy layer at the tooth surface, which layer consists of the base substance of the polished material, on the one hand, and of the polishing agent, on the other hand. In the polishing procedure these two (the base substance and the polishing agent) are closely mechanically attached to each other and fused. Thus, the polishing agent is mechanically rubbed in between the microscopic microcrystalline to atomic unevennesses and roughnesses of the surface and fused with same due to local overheating and formation of an eutectic mixture. If this concept is transferred to the tooth surface, then this could mean that by treatment with large amounts of the finely-divided apatite, the latter is pressed into the exposed small dentin channels. Since the material is the same as that of the hard substance of the tooth, the existing damages can heal if no interfering alien minerals will inhibit the fusion process. Furthermore, the amount of offered apatite must be large enough, and care must be taken to prevent the polished surface being torn open again and destroyed by other abrasive materials.

Further investigations have shown that an increased remineralization occurs, more specifically so with particle sizes of the apatite of less than 4 μm . After 20 applications in vitro, there was already observed a reduction in diameter of the dentin channels by about 50%.

Independently of this subsequent theoretical explanation, it has been established that the desired effect is obtained only if all of the conditions according to the present invention have been fulfilled.


Thus, it is the object of the present invention to provide a dentifrice for hypersensitive teeth containing an apatite having an average particle size of less than 10 μm and optionally a local anesthetic, which dentifrice is characterized in that it contains an amount at least 15% by weight of an apatite having an average particle size of less than 8 μm and an abrasion value (RDA) of less than 30 as the sole crystalline and polishing substance, no further soluble mineral salts being present.


The apatite to be used in the present invention may be hydroxylapatite, fluoroapatite, or a mixture thereof. It is essential that the amount, particle size, and abrasion value will be observed and maintained and that no other soluble mineral salts can exert any interfering effect.

Silicic acid has been proven to be a non-interfering substance which can be added in an amount of up to 10% by weight without adversely affecting the efficacy of the dentifrice.

The dentifrices according to the present invention of course may additionally contain a local anesthetic such as benzocain, p-aminobenzoic acid ethylester. In addition to glycerol and water, the dentifrices according to the present invention further contain wetting and foaming agents, flavoring agents, and aroma ingredients. If desired, any other additive may be used as long as it is not a soluble mineral salt.

The apatite used in the present invention and having an average particle size of less than 8 μm and an abrasion value (RDA) of less than 30 is known in the art as so-called amorphous hydroxylapatite, fluoroapatite or a mixture thereof. The bulk density of the apatite is preferably less than 180 g/l and mostly in the range of around 150 g/l.

The dentifrice according to the present invention is further illustrated by the following Example and Comparative Examples and Abrasion Tests.

EXAMPLE Tooth-paste (Recipe A)

______________________________________Amorphous silicic acid Aerosil 200                     2.40%Carboxymethylcellulose    1.00%Sodium laurylsulfate      2.75%Glycerol (99%)            20.80%Wetting agent (Hostapon KTW)                     0.90%p-Hydroxybenzoic acid methylester-Na                     0.20%Saccharin-Na              0.25%Tricalcium hydroxylapatite                     17.00%Water                     50.699%S-Erythrosin 76 E 127     0.001%Aroma                     1.50%Propylene glycol          2.50%______________________________________

The tooth-paste consisting of the above components was subjected to the abrasion test (RDA). The abrasion value was found to be 24.

Clinical examinations of this tooth-paste showed a significant improvement already after 3 to 8 days, and all of the users were found to be pain-free after 15 days at the latest.


For comparison, the formulations according to the recipes B through G as set forth in the following Table were prepared.

                                  TABLE__________________________________________________________________________              B   C   D   E   F   G__________________________________________________________________________Amorphous silicic acid Aerosil 200              3.00                  2.85                      10.00                          3.00                              2.40                                  2.40Carboxymethylcellulose              1.00                  1.00                      1.00                          1.00                              1.00                                  1.00Sodium laurylsulfate              2.75                  2.75                      2.75                          2.75                              2.75                                  2.75Glycerol (99%)     20.80                  20.80                      20.80                          20.80                              20.80                                  20.80Wetting agent (Hostapon KTW)              0.90                  0.90                      0.90                          0.90                              0.90                                  0.90p-Hydroxybenzoic acid methylester-Na              0.20                  0.20                      0.20                          0.20                              0.20                                  0.20Saccharin-Na       0.25                  0.25                      0.25                          0.25                              0.25                                  0.25Tricalcium hydroxylapatite              --  --  --  9.00                              17.00                                  17.00Water              49.499                  49.499                      60.99                          49.499                              44.699                                  44.699S--Erythrosin 76 E 127              0.001                  0.001                      0.001                          0.001                              0.001                                  0.001Aroma              1.50                  1.50                      1.50                          1.50                              1.50                                  1.50Propylene glycol   2.50                  2.375                      2.50                          2.375                              2.50                                  2.50Potassium sulfate  0.175                  --  --  0.175                              --  --Magnesium carbonate              1.25                  --  --  1.25                              --  --Sodium hydrogencarbonate              6.25                  --  --  6.25                              --  --Sodium chloride    0.175                  --  --  0.175                              --  --Titanium dioxide   0.75                  0.75                      --  0.75                              --  --Dicalcium phosphate ×  2 H2 O              9.00                  17.00                      --  --  --  --Benzocain          --  0.125                      --  0.125                              --  --Strontium chloride × 6 H2 O              --  --  --  --  6.00                                  5.00Cetylamine hydrogenfluoride              --  --  --  --  --  1.00__________________________________________________________________________

Recipe E conforms to that of the commerical product of German Patent Specification No. 21 34 862. Recipe B conforms to that of the commercial product of Recipe E; however, Recipe B does not contain hydroxyl apatite. Recipe C conforms to Recipe B, but contains benzocain added thereto. Recipe D is a placebo containing no active ingredient at all. Recipes F and G conform to Recipe A according to the invention; however they additionally contain strontium chloride×6 H2 O or cetylamine hydrogenfluoride, respectively.

As a result of the clinical examination, Recipe A (a dentifrice according to the present invention) was found to be substantially more efficient than the commercial product and some other recipes, although the latter were superior to the placebo.


The abrasion values (RDA) were determined of the materials according to Recipes A and F and of some known commercial products. It was determined that the abrasion value of Recipe F was already 61. The respective values for the commercial products Blend-a-med, Lacalut, Theramed and Causamed were between 85 and 95.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US4048300 *Jan 19, 1976Sep 13, 1977Colgate-Palmolive CompanyDental preparation containing materials having calcium and phosphate components
US4177258 *Mar 14, 1979Dec 4, 1979Colgate Palmolive CompanyDentifrice for dental remineralization
US4183915 *Oct 13, 1978Jan 15, 1980Colgate-Palmolive CompanyStable solution for dental remineralization
US4327079 *Oct 29, 1980Apr 27, 1982Dental Chemical Co., Ltd.Dentifrice compositions
US4342741 *Apr 27, 1981Aug 3, 1982Dental Chemical Co., Ltd.Dentifrice compositions
US4634589 *May 7, 1985Jan 6, 1987Wurttembergische Parfumerie-Fabrik GmbhDentifrice for hypersensitive teeth
DE2134862A1 *Jul 13, 1971Jan 25, 1973Scheller Durodont DrMouth-and dental-care prepns - contg hydroxyl-apatite and/or disinfectants
Non-Patent Citations
1 *Koldermann et al., C.A. 78 128425v, (1973), of Ger. Offen. 2134862, 1/25/73.
2Koldermann et al., C.A. 78# 128425v, (1973), of Ger. Offen. 2134862, 1/25/73.
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US5009898 *Sep 19, 1989Apr 23, 1991Kabushiki Kaisha SangiMedicine, dentistry; teeth, bone replacements
US5037639 *May 24, 1989Aug 6, 1991American Dental Association Health FoundationMethods and compositions for mineralizing calcified tissues
US5087444 *Mar 27, 1990Feb 11, 1992Beecham Group P.L.C.Non-fluoride desensitizing mouthwash
US5139768 *Feb 28, 1991Aug 18, 1992Yissum Research Development Company Of The Hebrew University Of JerusalemDental composition for hypersensitive teeth
US5211939 *Jan 14, 1992May 18, 1993Gillette CanadaMethod for desensitizing teeth
US5250288 *Jan 25, 1993Oct 5, 1993Gillette Canada, Inc.Applying charged polymeric particles
US5252577 *Mar 6, 1992Oct 12, 1993Gillette Canada, Inc.Applying a barbiturates
US5307353 *May 7, 1991Apr 26, 1994Fujitsu LimitedFault recovery system of a ring network
US5328692 *Oct 29, 1992Jul 12, 1994Dominique DanaNew liquid dentifrice composition
US5403577 *Jun 12, 1992Apr 4, 1995Yissum Research Development Company Of The Hebrew University Of JerusalemSustained release oral varnish consists of antihypersensitive agent embedded in a carrier such as cellulose or hydrophobic polymer
US5437857 *Aug 9, 1993Aug 1, 1995American Dental Association Health FoundationA deposited apatite is formed on teeth in situ after applying a mixed solution of amorphous calcium compound and a material forming amorphous calcium phosphate, calcium phosphate fluoride or calcium carbonate phosphate
US5438076 *Jan 4, 1993Aug 1, 1995Perio Products, Ltd.Removing or suppressing oral plaque by topical application of mixture of bacteriocides, release-controlling agents and film-forming anionic copolymers of (meth)acrylic acids and esters and acrylates substituted by quaternary ammonium groups
US5468489 *Jun 20, 1994Nov 21, 1995Sangi Co., Ltd.Dentifrice containing antibacterial material
US5522726 *Oct 27, 1994Jun 4, 1996Hodosh; MiltonApplying composition having high potassium concentration; does not require injection into gum
US5534244 *May 6, 1994Jul 9, 1996Tung; Ming S.Applying to teeth compounds which will form strontium containing apatite, dentistry
US5648399 *Apr 25, 1995Jul 15, 1997Perio Products, Ltd.Liquid polymer composition and method of use
US5660817 *Nov 9, 1994Aug 26, 1997Gillette Canada, Inc.Desensitizing teeth with degradable particles
US5741479 *Jun 6, 1995Apr 21, 1998Gillette Canada Inc.Blocking exposed tubules
US5849266 *Apr 4, 1995Dec 15, 1998Perio Products Ltd.Dental composition for hypersensitive teeth
US6241972Feb 19, 1999Jun 5, 2001Block Drug Company, Inc.Dentifrice including a desensitizing agent comprising an addition copolymer of a long-chain a-olefin hydrophobic monomer and a hydrophilic partially/fully hydrolyzed acrylic monomer or its salt
US6919070 *Oct 17, 1997Jul 19, 2005Zakrytoe Aktsionernoe Obschestvo “OSTIM”Stomatic composition
US7919107Jul 28, 2008Apr 5, 2011Sudzucker Aktiengesellschaft Mannhein/OchsenfurtMethod for treating hypersensitive teeth
EP1731132A1Oct 10, 2001Dec 13, 2006Block Drug Company, Inc.Dental compositions for hypersensitive teeth
WO2008040723A1Oct 2, 2007Apr 10, 2008Fritz LeyDental, particularly remineralizing composition, effective for pain sensitive teeth, and dental particles, particularly for said composition
U.S. Classification424/49, 424/52, 424/57, 424/673
International ClassificationA61Q11/00, A61K8/24, A61K8/00
Cooperative ClassificationA61Q11/00, A61K8/24
European ClassificationA61K8/24, A61Q11/00
Legal Events
Feb 6, 1996FPExpired due to failure to pay maintenance fee
Effective date: 19951206
Dec 3, 1995LAPSLapse for failure to pay maintenance fees
Jul 11, 1995REMIMaintenance fee reminder mailed
May 28, 1991FPAYFee payment
Year of fee payment: 4